Rotavirus is a segmented, double-stranded RNA virus that is the major cause of severe gastroenteritis in infants and young children. Profound fluid and electrolyte loss often leads to hospitalization for life-saving rehydration therapy. Where access to medical care is limited or unavailable, volume depletion, shock and death can occur. Annually, nearly one million childhood deaths in developing countries have been ascribed to inadequately treated rotavirus gastroenteritis. In the industrialized world, more than 30% of the children admitted to hospitals with acute gastroenteritis have rotavirus infections.